Get the one kit G.Skill RipjawsX DDR3-2133. Because the i4770K support up to 1600mhz ram, over that you need OC the ram and also you need up the voltage too that why the 2133mhz has the 1.6V. But don't over 1.65V. The 1.5V is for standard 1600mhz RAM only.
Yep 1.5 is basically aimed at the recommended DRAM of 1333/1600 calls for when running the CPU at stock. I stick with 1.5 on 1866 and below, from 2133 on up 1.6-1.65 is perfectly fine, though don't buy over 1.65